Application of tomographic reconstruction techniques for density analysis of green bodies

Abstract

Progress in the manufacturing of ceramics, but also of sintered metals, strongly relies on the evaluation of the density distribution in green bodies. This evaluation is crucial from many points of view, including the calibration of constitutive models for in-silico simulation of densification processes. To this end, X-ray tomography and other techniques are possible but can be unmanageable for some institutions. Therefore, a destructive method is introduced in the present article to measure the density field of a green body sample using a CNC mill, an analytical balance, and analysis techniques from the field of computational tomography. A virtual experiment is presented where the method is used to reconstruct a simulated green body density field and is found to satisfactorily correspond to the original solution. The green body density field of a truncated cylinder made of alumina powder is evaluated using this method and the reconstructed field is presented.

Thermomechanical modelling of ceramic pressing and subsequent sintering

“…Before sintering, a green body is obtained through powder compaction and, depending on the geometry and the compaction method, the pressed green body shows usually significant differences of local density throughout the part [8,9], so that powder pressing has a strong influence on sintering, which depends on the (relative) density of the green. Therefore a continuum model that can predict the density distribution after the pressing step and the subsequent sintering is important for industrial applications [10].…”